Wireless ultra-wide-band (UWB) tracking tags are used to track the location of athletes on a sporting field. Attaching tracking tags to athletes presents a challenge to the system designer. These tracking tags are designed to be as small as possible and are commonly mounted to shoulder pads of the athletes for contact sports, such as American Football. However, when positioned near the human body, transmission performance of the tracking tag is degraded.
The electrically short monopole antenna of the tracking tag is a wide-band and compact radiating element for the tracking tag. However, the human body and the pads are mostly absorptive of energy at UWB frequencies. Since the tracking tags are asymmetrically mounted onto the body, the typical omnidirectional pattern of the short monopole antenna results in loss of energy in one or more directions, such as when the energy is absorbed by the human body or shoulder pads.